JPH1142501A - Vibration cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase rigidity in a back component force direction in a passive vibration cutting device and make surface roughness excellent by making a cutting tool elastically displaceable in the circumferential and axial directions of an axis orthogonal to the cutting edge direction of the cutting tool, and vibrating the cutting tool both circumferentially and axially by cutting resistance. SOLUTION: A holder shaft 1 is a cylindrical body supported concentrically with the center axis A of a tool body 2 and is elastically displaceable in the circumferential and axial directions of the center axis A. A cutting tool holder 3 and the holder shaft 1 are not easily vibrated in a back component force direction compared to a main component force direction and a feed component direction, that is, are of structure particularly high in rigidity in the back component force direction. When main component force or feed component force acts upon the cutting tool holder 3 and holder shaft 1 due to cutting resistance generated to a cutting tool 8, the cutting tool holder 3 and holder shaft 1 are torsionally vibrated around the center axis of the tool body 2 and simultaneously vibrated in and axial direction along the center axis A. The surface roughness of a workpiece can therefore be made excellent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vibration cutting device. More specifically, in a passive vibration cutting device that does not require a vibrating device, the rigidity in the direction of the back force is enhanced.

[0002]

2. Description of the Related Art As a conventional vibration cutting apparatus, there is known a vibration cutting apparatus in which forcible vibration is applied to a cutting blade to reduce cutting resistance and improve effects such as improvement of machining accuracy (Japanese Patent Publication No. Hei. -92001). The applicable range is the one that is mounted on the main shaft of the machine tool and rotates to cut the workpiece, such as a drill or a mill, and the cutting tool is used for the rotating cylindrical workpiece such as a lathe or planing machine. There is one that presses and cuts.

[0003]

As the above-mentioned vibration cutting device, for example, as shown in FIG. 6, an L-shaped notch 02 is inserted into a bite holder 01 in a length direction to form a bifurcated shape. A tip for holding the chip 03 is formed in one of the forked portions, while the piezoelectric element 0
4 is inserted.

The piezoelectric element 04 generates a vibration in the thickness direction of the cut 02 by energization. The vibration is the tool holder 0
1 bending stiffness k, mass m at the tip of the tool holder 01
Is transmitted to the chip 03 in response to Therefore, by energizing and vibrating the piezoelectric element 04, the bite holder 01 holding the chip 03 is bent, and the chip 03 vibrates in the direction indicated by the arrow in the figure.

[0005] By forcibly applying vibration to the chip 03 in this manner, cutting resistance is reduced, tool life is extended, and chip processing is facilitated by cutting chips. However, such a vibration cutting tool requires a vibrating device such as a piezoelectric element 04 or an ultrasonic oscillator in order to forcibly apply vibration to the chip 03, and further electrically controls the piezoelectric element 04 and the like. It also requires ancillary equipment.

Therefore, a vibration cutting device which does not require the above-mentioned vibration generating device has been developed (Japanese Patent Publication No. 7-24965). When the structure is applied to a vibration cutting tool, for example, the structure shown in FIG. 7 can be considered. This vibrating cutting tool has an L-shaped notch 06 in the bite holder 05 in the length direction to form a bifurcated shape.
7 is inserted, and the mover 07 is pressed in the axial direction by the spring 08. The other forked portion constitutes a tip portion for holding the chip 09, and the movable element 07 comes into contact with a rear recess of the tip portion.

Therefore, the cutting tool generated in the chip 09 causes the bite holder 05 holding the chip 09 to bend, while the movable element 07 is pressed by the spring 08 and comes into contact with the tip of the bite holder 05 to vibrate. . This vibration is transmitted to the tip 09 according to the spring constant k ₁ of the spring 08, the bending rigidity k _{2 of} the tool holder 05, the mass m _{1 of the} mover 07, and the mass m ₂ of the tip of the tool holder 05, 09 vibrates as shown by the arrow in the figure.

However, in such a passive vibration cutting tool utilizing vibration generated by the chip 09, the contact portion is a vibration source, that is, a non-linear vibration portion.
There is a disadvantage that uniform vibration cannot be obtained, and the generation of vibration is unstable, and the durability and the aging characteristic are weak.

In particular, in a lathe or the like, if vibration occurs in the cutting direction of the cutting tool, chatter vibration may occur, and the accuracy of the diameter may deteriorate. Further, as shown in FIG. 8, when the stress applied to the cutting tool is decomposed into three orthogonal feed components, a main component force, and a back component force, the chatter vibration is reduced if the rigidity mainly in the back component direction is low. It has been found that the surface roughness is easily generated and the surface roughness is deteriorated. The present invention has been made in view of the above prior art, and in a passive vibration cutting device, a vibration capable of improving surface roughness in vibration cutting by increasing rigidity in a direction of a back force. An object is to provide a cutting device.

[0010]

According to a first aspect of the present invention, there is provided a vibration cutting apparatus for cutting a workpiece, wherein a cutting tool for cutting a workpiece is provided with an axis perpendicular to a cutting direction of the cutting tool. The shaft is elastically displaceable in the circumferential direction and the axial direction, and vibrates in both the circumferential direction and the axial direction due to cutting resistance. In the vibration cutting device according to claim 2 of the present invention that achieves the above object, according to claim 1, the cutting tool is fixed on a rigid cutting tool holder, and the cutting tool is respectively disposed in a circumferential direction and an axial direction of the shaft. It is characterized by being supported so as to be elastically displaceable.

According to a third aspect of the present invention, there is provided a vibration cutting apparatus according to the second aspect, wherein the shaft is a center axis of a tool body attached to the cutting machine, and the cutting tool holder is the shaft. The holder shaft is integrally fixed to a holder shaft that is concentric with the tool shaft, and the holder shaft is slidably supported by the tool body via bearings in the circumferential direction and the axial direction of the shaft. According to a fourth aspect of the present invention, there is provided a vibration cutting apparatus according to the third aspect, wherein the holder shaft is connected to the tool main body via an elastic means, and the periphery of the shaft is rotated by the elastic means. It is characterized in that it can be elastically displaced in both the direction and the axial direction.

According to a fifth aspect of the present invention, there is provided a vibration cutting apparatus according to the fourth aspect, wherein the elastic means is arranged so as to extend in the axial direction when the holder shaft is displaced in the circumferential direction of the shaft. It is characterized by being a leaf spring which is deformed so as to change its dimension in the circumferential direction when it is displaced.

According to a sixth aspect of the present invention, which achieves the above object, the vibration cutting apparatus according to the fifth aspect, wherein the leaf spring is
The tool body and the holder shaft are connected via a mass having a predetermined mass and displaceable in a circumferential direction and an axial direction of the shaft, and a leaf spring on the tool body side and a leaf spring on the holder side Is characterized by being provided in a state of being inclined in opposite directions to each other.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

1 to 5 show a self-excited vibration cutting device according to an embodiment of the present invention. FIG. 1 is a perspective view of the vibration cutting device of the present embodiment, FIG. 2 is a longitudinal sectional view of the vibration cutting device, FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2, and FIG. IV-
FIG. 5A is a view taken in the direction of the arrow VV in FIG. 2.

As shown in FIG. 1, a window 2a through which a cutting tool 8 protrudes is formed on a peripheral surface in a substantially cylindrical tool body 2.
On the other hand, a tool holder 3 for fixing a tool 8 and a holder shaft 1 are inserted into the tool body 2. The tool axis 1 is located inside the tool body 2
The cylindrical body is supported concentrically with the central axis A, and is elastically displaceable in the circumferential direction of the central axis A of the tool main body 2 and in the axial direction of the central axis A.

The tool holder 3 is fastened by penetrating the tool shaft 1 in a direction perpendicular to the axis, and has a tool 8 attached to the end thereof. The tool 8 projects from the window 2a of the tool body 2. The cutting direction of the cutting tool 8 coincides with the axial direction of the cutting tool holder 3, so that the back force generated by cutting by the cutting tool 8 is reduced by the center axis A of the tool body 2.
, The feed force is generated along the central axis A of the tool body 2, and the main component force is generated around the center axis of the tool body 2.

Here, the tool holder 3 and the tool shaft 1
Has a structure that is less likely to vibrate in the back component direction than the main component direction and the feed component direction, that is, has a particularly high rigidity in the back component direction. That is, the tool axis 1 is attached to the tool body 2
, One end thereof is slidably supported on the inner peripheral surface of the tool body 2 via a bearing 9 in the circumferential direction of the central axis A and in the direction along the central axis A.

A spring 4, a mass 5 and a spring 6 are connected to the other end of the cutting tool shaft 1 in the axial direction. Axis A
Are connected so as to be elastically displaceable in a direction along the axis. Here, the mass 5 is a cylindrical shape having a predetermined mass, and is supported at a constant interval on the inner peripheral surface of the tool main body 2.

The spring 4 connecting the mass 5 and the cutting tool 1 is
Four leaf springs 4a arranged at 90 degree intervals in the circumferential direction,
The springs 6 connecting the mass 5 and the mounting plate 7 include four leaf springs 6a, 6b, 6c, 6d arranged at 90-degree intervals in the circumferential direction. Each of the leaf springs 4a to 4d and 6a to 6d is inclined at about 45 ° in the same direction along the circumferential direction as shown in FIGS. 4 (a) to 4 (e) and 5 (a) to 5 (e). Attached and leaf spring 4a
4d and the leaf springs 6a to 6d have opposite inclination directions.

Accordingly, when a main component force or a feed component force acts on the tool holder 3 and the tool shaft 1 due to the cutting resistance generated in the tool 8, the vibration is generated by the spring 4, the mass 5 and the spring 6
When transmitted, the leaf springs 4a to 4d and 6a to 6d bend and vibrate around the central axis A of the tool body 2 and simultaneously vibrate in the axial direction along the central axis A. .

Here, each leaf spring 4a-4d, 6a-6d
A phase difference between the vibrations of the leaf springs 4a to 4d and 6a to 6d by combining conditions such as the mass of the mass 5 and the total mass of the cutting tool 1 and the cutting tool holder 3 according to the spring constant of For example, if the phase difference is 90
It is also possible to set a resonance state by setting the angle to 180 °.

More specifically, when a main force or a feed force acts on the tool holder 3 and the tool shaft 1 due to the cutting resistance generated on the tool 8, first, the spring 4 bends and the tool holder 3 and the tool shaft 1 are bent. Vibrates around the central axis A of the tool body 2 at the same time as vibrates in the axial direction along the central axis A. Then, the vibration is transmitted to the spring 6 via the mass 5, and the spring 6 is compared with the spring 4. The phase is bent 90 ° to 180 ° later, so that the tool holder 3 and the tool shaft 1 are further bent.
Vibrates around the central axis A of the tool body 2.

If such a phase difference is set, the cutting tool 8 at the tip of the cutting tool holder 3 vibrates so as to draw a figure 8 on a plane perpendicular to the cutting tool axis, so that chips generated by cutting can be shortened. You will be divided. In this way, while the main component force and the feed component force generated during cutting generate vibrations in two directions in combination, the back component force direction allows elastic displacement in a direction perpendicular to the center axis A. Since the elastic means is not provided, and the cutting tool shaft 1 is in a state of a simple support beam supported at both ends by the bearing 9, the spring 4, the mass 5, and the spring 6,
It has a structure with high rigidity.

In particular, each of the springs 4 and 6 is a leaf spring 4a.
4e and 6a to 6e are arranged at quadrant positions in the circumferential direction, so that they can be elastically displaced in the circumferential direction around the central axis A and in the direction along the central axis A. On the other hand, it is a structure that is not easily elastically displaced in the back force direction. As described above, since the vibration cutting tool of the present embodiment has high rigidity in the direction of the back force, chattering hardly occurs at the time of cutting, and it is possible to maintain good surface roughness.

In the above-described embodiment, one end of the holder shaft 1 is supported by the bearing 9. However, in order to increase the rigidity in the direction of the back force, both ends of the holder shaft 1 are held by bearings. You may do it. Further, in the above embodiment, each of the springs 4 and 6 is composed of four leaf springs. However, in order to increase the rigidity in the direction of the back force, further leaf springs may be provided.

[0027]

As described above in detail with reference to the embodiment, according to the first aspect of the present invention, the cutting tool vibrates in the circumferential direction and the axial direction of the shaft due to the cutting resistance.
The vibration reduces the cutting resistance, improves the processing accuracy, and has the effect of cutting the chips finely. Further, according to this, since the rigidity of the cutting tool in the direction of the back force can be increased, chatter vibration can be suppressed and the surface roughness of the workpiece can be improved. According to the second aspect of the present invention, the cutting tool is fixed on a rigid holder, and the cutting tool vibrates in the above two directions. There is an effect that can be realized. According to the third aspect of the present invention, the holder is fixed to the holder shaft, and the holder shaft is supported by the tool body via a bearing so as to be able to vibrate in the two directions. There is an effect that the rigidity can be surely increased. According to the fourth aspect of the present invention, since the holder shaft is connected to the tool body via the elastic means so as to be capable of vibrating in the two directions, the cutting tool can be easily vibrated and the vibration of the cutting tool is smooth. And become regular,
This has the effect of reducing noise. According to the fifth aspect of the present invention, the elastic means is a leaf spring, and the leaf spring acts so as to mutually convert the vibrations in the two directions.
There is an effect that this two-way vibration can be reliably realized. Further, according to the invention of claim 6, the leaf spring connects the tool body and the holder shaft via the mass displaceable in the two directions, and the leaf spring is connected to the tool body side and the holder shaft side. Are inclined in opposite directions to each other, so that there is an effect that the above-described invention of claim 5 can be realized easily and reliably.

[Brief description of the drawings]

FIG. 1 is a perspective view of a vibration cutting device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the vibration cutting device according to one embodiment of the present invention.

FIG. 3 shows a vibration cutting tool according to one embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along line III-III in FIG.

FIG. 4A is a view of the vibrating cutting tool according to one embodiment of the present invention, taken along the line IV-IV in FIG. 2, and FIG.
4 (b), (c), (d), and (e) respectively show b in FIG.
It is an arrow view of the leaf spring along the -b line, the cc line, the dd line, and the ee line.

FIG. 6A is a view of the vibrating cutting tool according to one embodiment of the present invention, taken along the line VV in FIG. 2, and FIG.
(B), (c), (d), and (e) correspond to b in FIG.
It is an arrow view of the leaf spring along the -b line, the cc line, the dd line, and the ee line.

FIG. 6 is a front view of a conventional vibration cutting device using a piezoelectric element.

FIG. 7 is an explanatory view of a passive vibration cutting device.

FIG. 8 is an explanatory diagram showing a component force generated by a cutting resistance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Holder shaft 2 Tool body 3 Tool holder 4 Spring 5 Mass 6 Spring 7 Mounting plate 8 Tool 9 Bearing

Claims (6)

[Claims] 1. A cutting tool for cutting a workpiece is elastically displaceable in a circumferential direction and an axial direction of the cutting tool with respect to an axis orthogonal to a cutting direction of the cutting tool. A vibration cutting device characterized by vibrating in the axial direction. 2. The tool according to claim 1, wherein the tool is fixed on a tool holder having rigidity, and the tool holder is supported so as to be elastically displaceable in a circumferential direction and an axial direction of the shaft. Vibration cutting equipment. 3. The shaft is a central shaft of a tool body attached to a cutting machine, the tool holder is integrally fixed to a holder shaft concentric with the shaft, and the holder shaft is connected to the holder shaft through a bearing. 3. The tool body is slidably supported in a circumferential direction and an axial direction of the shaft.
The vibration cutting device according to the above. 4. The tool according to claim 1, wherein the holder shaft is configured to
The vibration cutting device according to claim 3, wherein the vibration cutting device is connected via an elastic means, and is elastically displaceable in a circumferential direction and an axial direction of the shaft by the elastic means. 5. The elastic means is a leaf spring which is deformed to change its dimension in the axial direction when the holder shaft is displaced in the circumferential direction of the shaft and in the circumferential direction when displaced in the axial direction. The vibration cutting device according to claim 4, wherein the vibration cutting device is provided. 6. The tool spring has a predetermined mass, and connects the tool body and the holder shaft via a mass which is displaceable in a circumferential direction and an axial direction of the shaft, and is connected to the tool body. The vibration cutting device according to claim 6, wherein the leaf spring and the leaf spring on the holder side are provided in a state of being inclined in directions opposite to each other.